Recording tensiometer



Nov. 13, 1956 v E. N. scHwENNlNGER ETAL 2,770,127

RECORDING TENSI'OMETER Filed Sept. 18, 1952 RECEIVING RECORDER .PRESSURE GAUGE SOURCE OF COM PRESS E D INVENTORS.

EARNEST N. SCHWENNINGE v JAMES H. HOFFMAN United States Patent C RECORDING TENSIOMETER Earnest N. Schwenninger and James H. Hoffman, Cumberland, Md., assignors to Celanese Corporation of America, New York, N. Y., a corporation of Delaware Application September 18, 1952, Serial No. 310,226

9 Claims. (Cl. 73-143) This invention relates to a recording tensiometer and more particularly to a tensiometer for recording lluctuations in yarn tension.

It is often desirable in textile operations to ascertain the tension in running yarns, particularly since many fabric defects and dyeing properties are related to yarn tension and to changes in such tension. However, owing to the large and rapidly occurring variations of the tension in running yarns, it has been diicult to record the tension continuously, in a precise manner, and without a relatively large movement of the yarn-receiving portion of the tension-measuring device.

It is an object of this invention to provide an accurate and respo-nsive tensiometer for recording the fluctuations in the tension of a running yarn or filament as it passes over rollers or guides in predetermined arranged courses.

It is a further object of this invention to provide a force measuring device in which the measurement of the force involves only a small movement of the force-receiving portion of the device.

Other objects of this invention, together with certain details of construction and arrangements of parts, will be apparent from the following description and claims.

In accordance with the present invention there is provided a tensiometer including a movable member which has a predetermined equilibrium position and which is urged away from that position by the tension of the yarn. There are also provided means for applying to the movable member a force opposing the tension of the yarn, so as to maintain the movable member in its equilibrium position, and means, actuated by movement of the movable member away from equilibrium positioned, for varying this opposing force. When the tension in the yarn changes, the movable member moves slightly away from its equilibrium position, since the yarn tension is no longer exactly balanced by the force opposing the yarn tension. This movement away from equilibrium position actuates the means for varying the force opposing the yarn tension, so as to increase or decrease this opposing force in order to return the movable means to its equilibriurn position. The tensiometer of this invention is also provided with means which are movable in response to the magnitude of the force opposing the yarn tension, e. g. means for measuring such opposing force. The measurement of the force opposing the yarn tension constitutes an indication of the magnitude of the yarn tension and of the changes in yarn tension.

More particularly, the tensiometer of our invention is provided with a pivoted lever carrying a roller over which the yarn passes and with a chamber which is connected through valves to a source of compressed air and to an outlet to the atmosphere. The pressure of the air in the chamber is exerted on the pivoted lever through a diaphragm in such a manner that the tendency of the lever to tilt in response to the tension of the yarn is opposed by the pressure of the air in the chamber. By this means the lever is maintained in its equilibrium position. A recording device continuously records the pressure of the rice air in the chamber and thereby provides a continuous indication of the tension in the yarn. The construction is such that an increase in yarn tension causes the lever to be tilted in one direction slightly, temporarily, since the air pressure is not suflicient to balance the increased yarn tension. This tilting causes a valve to admit compressed air to the chamber to build up the air pressure therein and thus to force the lever back into its equilibrium position. Similarly, a decrease in the yarn tension causes the lever to be tilted slightly in the other direction, since the air pressure now overbalances the yarn tension. Such tilting in the other direction causes a valve to connect the chamber to the atmosphere with the result that air rushes out of the chamber until the pressure therein has declined sufficiently to permit the lever to return to its equilibrium position. Thus the tensiometer effects variations in the air pressure in accordance with the variations in yarn tension, and a recording of the variations of air pressure provides a recording of the variations of yarn tension.

In the drawing wherein a preferred embodiment of our invention is shown:

Fig. l is a plan view of the recording tensiometer of this invention with certain portions omitted in the interests of clarity,

Fig. 2 is a sectional elevation of the recording tensiometer taken on the line 2-2 of Fig. 1 in the direction of the arrows, and with certain portions shown in section and other portions omitted,

Fig. 3 is a plan view of the base of the recording tensiometer.

Referring now to the drawing for a detailed description of this invention, the reference numeral 11 indicates generally a collecting transmitter. This collecting transmitter carries a roller 12 over which a yarn, designated by reference numeral 13, may be passed under tension. Roller 12 is mounted for rotation in the forked end 1S of a lever 16 which has depending ears 17, straddling the base 18 of the collecting transmitter and journaled on a hardened steel shaft 19 carried by base 18.

Lever 16 is provided with a screw-threaded extension 22 on which is adjustably mounted a screw-threaded counter-weight 23. In the base 18 is a chamber 24 which communicates by means of a port 26 with a valved passageway 27, which in turn communicates with another valved passageway 28 by means of a slot 29. Extending across the entire top of the base 18 is a diaphragm 31 of any suitable material such as fabric reinforced rubber over which is a cover`32 which contains circular opening 33 aligned with chamber 24, opening 34 aligned with passageway 27 and opening 36 aligned with passageway 28. The cover 32 is held to the base 18 by means of screws 37 and serves to clamp the diaphragm 31 securely to the base so that no air can leak past the diaphragm into the passageways of the base. Three screws 38, 39, and 41 are adjustably carried by the lever 16 and are threaded in holes 42, 43, and 44, respectively, therein. Screw 38 is secured to a plate 46 which contacts the diaphragm 31 but is not attached thereto. Screws 39 and 41 abut directly against the diaphragm and are cen trally located with respect to passageways 27 and 28, respectively. Passageway 27 is provided with a valve seat 49, a screw plug 51 closing the lower part of the passageway and a helical spring 52, which is compressed between screw plug 51 and cone valve S3 normally to force the latter into engagement with valve seat 49. Valve 53 carries a stem 54, which, when valve 53 is in closed position in valve seat 49, abuts against diaphragm 31 opposite screw 39.v Valve 53 also carries another stern 56, the end of which fits into a recess 57 in screw plug 51. A similar arrangement is provided in passageway 28 and `which serves to force the latter into engagement with.

valve seat 58. Valve 62 carries a stem 63, which, when valve 62 is in closed position in valve seat 58, abuts against diaphragm 31 opposite screw 41. Valve 62 carries another stem 64, the end of which tits into a recess 66 in screw plug S9. Screws 39 and 41- are adjusted so that when lever 16 is in the position shown in the drawing, i. e. an equilibrium position, both valves 53 and 62 are closed, and so that a slight tilting movement of lever 16 in either direction will cause the opening of one or the other of these valves. In passageway 27 at a point below valve 53 a hole 67 is drilled, which holc is connccted to a source of low pressure compressed air 68 by means of pipe 69 (Fig. 3). Screw plug 59 is provided with a bleeder hole 71. The pressure in chamber 24 is communicated, through slot 29, opening 72 and pipe 73, to a Bourdon tube pressure gauge 74, or other means responsive to the magnitude of the pressure, and a receiving recorder 76. Receiving recorder 76 is a standard, calibrated, pressure recording instrument which inscribes the pressures on a graduated chart which is moved at a constant speed, e. g. by clockwork, so as to produce a graph of air pressure in the chamber 24 versus time. The indicator on the pressure gauge 74 and the chart of the receiving recorder 76 may be calibrated to convert the reading of the pressure into a reading of the corresponding tension on the yarn, so that a direct reading of the yarn tension in terms of grams may be obtained.

In the operation of the tensiometer the yarn 13 passes continuously under tension over roller 12. The force ou the roller 12 tilts lever 16 and moves screw 39 downwardly, thus pushing down valve 53 which then allows compressed air from supply 68 to flow through pipe 69, hole 67, passageway 27 and port 26 into chamber 24 until the pressure in chamber 24 forces diaphragm 31, plate t6 and screw 38 upwardly, tilting the lever 16 and allowing valve 53 to rise and shut off the supply of compressed air. The lever 16 is now in a balanced or equilibrium position. When the tension on the yarn increases, this same sequence of events will be repeated, with lever 16 tilting from its equilibrium position, causing valve 53V to open and allowing a rise in the pressure under the diaphragm 31, which causes lever 16 to be moved back to its equilibrium position. When the tension on the yarn decreases, the pressure of the air in chamber 24 will no longer be balanced by the force exerted by the yarn on roller 12, and this air pressure will force the diaphragm 31, plate 46 and screw 38 upwardly, thus tilting the lever 16 and forcing screw 41 downwardly to open valve 62 and allow air to escape from chamber 24 through port 26, slot 29, passageway 28' and hole 71 until the air pressure in chamber 24 decreases enough so that the lever 16 will return to its equilibrium position causing valve 62 to close. The pressure of the air under the diaphragm 31 is inscribed on receiving recorder 76 and also indicated by pressure gauge 74.

It is to be understood that the foregoing detailed description is given merely by way of illustration and that many variations may be made therein without departing from the spirit of our invention.

Having described our invention, what we desire to secure by Letters Patent is:

1. A device for recording the tension in a moving yarn comprising means movable from a predetermined equilibrium position in response to a change in the tension on the yarn, said means including a roller over which the yarn passes, a member having a chamber, a source of fluid pressure connected to said chamber, means for transmitting the fluid pressure in said chamber to said movable means, means, actuated by the movements of` said movable means in responseto increases and decreases of said tension, for returningV said movable means 4, to said equilibrium position by a change in liuid pressure in said chamber and means for recording the lluid pressure in said chamber. i

2. A device for recording the tension in a moving yarn comprising means movable from a predetermined equilibrium position in response to a change in the tension on the yarn, said means including a roller over which the yarn passes, a member having a chamber, a source of Huid pressure connected to said chamber, means for transmitting the fluid pressure in said chamber to said movable means, means, actuated by the movements of said movable means in response to increases and decreases of said tension, for returning said movable means tosaid equilibrium position by a change in fluid pressure in said chamber, said rcturningmeans being so constructed and arranged that movement of said movable means in one direction away from said equilibrium position causes admission of the tluid under pressure tosaid chamber and movement of said movable means in another direction away from said equilibrium position allows luidto p ass out of said chamber, and means `for recording the uidprcssure in said chamber.

3. A device responsive to the tension in a moving yarn comprising means movable from a predetermined equilibrium position in response to a change in the tension on-the yarn, said means including a roller over which the yarn passes, a member having a chamber', a source of iiuid pressure-connectedto saidl chamber, means for trans- Imitting the Huid pressure in said chamber to said movable means, an outlet for said chamber, valve means between said chamber and said source and outlet, the valve means and the movable means being so linked that movement of Said movable means in one direction away from said equilibrium position connects said chamber to said, source and movement of said movable means in another direction away from said equilibrium position connects said chamber to said outlet, and means movable in response tothe magnitudel of the lluid pressurejn said chamber.

4. A device for recording the tension in a moving yarn comprising means movable from apredetermined equilibriumV position in response to a change in the tension on the yarn, said means including a roller over which the yarnpasses, a member having a chamber, a source of iiuid pressure connected to said chamber, means for transmitting/the fluid pressure in said chamber to said movable means, an outlet for said chambervalve means between said chamber and said source and outlet, the valve means and the movable means being so linked that movement of. said movable means in one direction away from said equilibrium position connects said chamber to said source and movement of said movable means in another direction away from said equilibrium position connects said chamber to said outlet, and means for recording the liuid pressure in said chamber.

5. A device for recording the tension in a moving yarn comprising` means movable from a predetermined equilibrium position in response` to a change in the tension on the yarn, said means including `a roller over which theA yarn passes, a memberhaving a chamber, a source of fluid pressure connected to said, chamber, a diaphragm for transmitting the fluid pressure in said chamber to said mov-able. means, an outlet for said chamber, valve means between said chamber sai-d source and outlet, the valve means land the movable means being so linked that movementof said movable means in one direction away from said equilibrium position connects said chamber to said source and movement of said movable means in another direction away from said equilibrium position connects said chamber to said outlet, and means for recording the duid pressure in said chamber.

6. A device for recording the tension in a moving y'arn comprising a lever movable from a predetermined equilibrium position in response ltoa change in the tension on the yarn,lsaid lever carrying a roller over which the yarn passes, a member having a chamber, a source of fluid pressure connected to said chamber, a diaphragm for transmitting the uid pressure in said chamber to said movable means, an outlet for said chamber, valve means between said chamber and said source and outlet, the valve means and the lever being so linked that movement of said lever in one direction away from said equilibrium position connects said chamber to said source and movement of said lever in another direction away from said equilibrium position connects said Chamber to said outlet, and means for recording the Huid pressure in said chamber.

7. A recording tensiometer for recording the tension in a moving yarn comprising a pivoted lever carrying a roller over which said yarn may pass, a source of compressed air, a base having a chamber and passageways connecting said chamber with said source of compressed air and with an opening to the atmosphere, a diaphragm covering said chamber, an adjustable member carried by said lever and engaging the top of said diaphragm above said chamber, a valve in the passageway between the chamber and the source of compressed air, said valve being spring-pressed to closed position, an adjustable member carried by said lever and operatively engaging said valve in such a manner that said valve is opened when said lever is tilted in one direction away from its equilibrium position, a second valve, said second valve being in the passageway between said chamber and said opening to the atmosphere and being spring-pressed to closed position, an adjustable member carried by said lever and operatively engaging `said second valve in such a manner that said valve is opened when said lever s tilted in the opposite direction away from its equilibrium position, said two latter adjustable members being so adjusted that neither valve is open when said lever is in its equilibrium position, and means for recording the pressure in said chamber.

8. A device for measuring the tension in a moving yarn, said device comprising yarn receiving means movable from 1a predetermined equilibrium position in response to change in the tension in the yarn, a member having a chamber operatively connected to said yarn receiving means, a source of fluid pressure connected to said chamber, means for transmitting uid pressure in said chamber to said yarn receiving means, means operated by lluid pressure in said chamber and actuated by movement of said yarn receiving means in response to changes in tension in the yarn for returning said yarn receiving means to said equilibrium position, and means for measuring the fluid pressure in said chamber.

9. A device for measuring the tension in a moving yarn comprising means movable from a predetermined equilibrium position in response to a change in the tension on the yarn, said means including a roller over which the yarn passes, a member having a chamber, a source of fluid pressure connected to said chamber, means for transmitting the fluid pressure in said chamber to said movable means, means, actuated by the movements of said movable means in response to increases and decreases of said tension, for returning said movable means to said equilibrium position by a change in fluid pressure in said chamber, and means for measuring the fluid pressure in said chamber.

References Cited in the le of this patent UNITED STATES PATENTS 1,872,087 Martin Aug. 16, 1932 1,987,815 Bartol Jan. 15, 1935 2,092,439 Bouhuys Sept. 7, 1937 2,099,955 Edwards Nov. 23, 1937 2,570,486 Roberts Oct. 9, 1951 2,581,990 Weber Ian. 8, 1952 2,593,906 Markson Apr. 22, 1952 2,655,037 Gess Oct. 13, 1953 

